diff --git a/libavcodec/vorbis_dec.c b/libavcodec/vorbis_dec.c
index a47cbc77ef..3ef56dc169 100644
--- a/libavcodec/vorbis_dec.c
+++ b/libavcodec/vorbis_dec.c
@@ -1579,7 +1579,7 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) {
 
 static int vorbis_decode_frame(AVCodecContext *avccontext,
                         void *data, int *data_size,
-                        uint8_t *buf, int buf_size)
+                        const uint8_t *buf, int buf_size)
 {
     vorbis_context *vc = avccontext->priv_data ;
     GetBitContext *gb = &(vc->gb);